An inline electron gun is one designed to generate or initiate preferably three electron beams in a common plane and to direct those beams along convergent paths to a point or small area of convergence near the tube screen. Inline electron guns all have a beam forming region and a main focus lens and may also include a prefocus lens. The beam forming region usually comprises the cathodes and three consecutive electrodes. A prefocus lens may comprise two or three electrodes. The main focusing lens is usually formed by two spaced electrodes.
Usually, the second electrode from the cathodes, called the G2 electrode, is plate-shaped. Such plate shape makes the G2 electrode subject to bending and flexing during electron gun operation. It is known to put small beads in the G2 electrodes to reinforce them. However, even with such reinforcement, these G2 electrodes still exhibit some flexing during gun operation.
Another problem that occurs in electron guns is arcing which may occur between the second and third electrodes from the cathodes (the G2 and G3 electrodes). Such arcing is enhanced when one of the electrodes has a protrusion on it that faces the other electrode.
The present invention addresses these problems by providing an improved construction for the beam forming region in an inline electron gun.